In order to maintain a single JVM, Oracle has created the HotRockit project to merge JRockit et Hotspot. Its results will be progressively integrated into Hotspot.

Since Java SE 7 update 4, Hotspot has same metrics as JRockit, which allows to use JRockit Mission Control with Hotspot. This one can be used 2 ways : with an eclipse plugin or with a command line.

Thanks to the eclipse plugin, Memleak analyser detects when the number of class instances is increasing and can visualize the call stack. After a run, Flight recorder can get event list in order to display heap and processor usage … In disconnected mode, it can also display memory leaks but not the graph of calls (visible only in connected mode).

The jcmd command (called jrcmd in JRockit) allows to run same queries as eclipse plugin. It can generate a .jfr file displayable with the eclipse plugin.

To finish, you must note that JRockit Mission Control is free for development but not for production and, according to François, it’s faster than profiling tools like Yourkit because metrics are implemented natively in the JVM.